Feedthrough insulator

ABSTRACT

A feedthrough insulator is characterized by the fact to comprises:&gt;-a central rod ( 10 ) which extends longitudinally with respect its longitudinal axis ( 10   y );&gt;-a sleeve ( 20 ) positioned coaxial around said rod of connection ( 10 ) with the respective circular shell ( 21 ) radially spaced (D- 21 ) with respect to the central rod ( 10 );&gt;-a sensor ( 30 ) of electric field and/or of magnetic field, positioned in proximity of the inner surface ( 22 ) of said shell ( 21 ) of the sleeve ( 20 ); and&gt;-a carrying body ( 40 ) formed by dielectric material able to contain and to embed said central rod ( 10 ), said sleeve ( 20 ) and said sensor ( 30 ) of electrical field and/or of magnetic field.

TECHNICAL FIELD

The present invention concerns a feedthrough insulator for electrical transformer tanks, electrical boxes, and other similar structures, in which said feedthrough insulator is able to sense the electrical field and/or the magnetic field generated by the live rod of connection of the same insulator, with the purpose, for example, to determine the value of the voltage and/or the value of the current of the same live rod of connection in relationship with the fields sensed.

More in particular, the present invention concerns a feedthrough insulator of the above type able to sense the electric field and/or the magnetic field generated by the live rod of connection without being affected by any surrounding electrical fields and/or magnetic fields, such as, for example, the electrical fields and/or the magnetic fields generated by other live conductors located nearby.

BACKGROUND OF THE INVENTION

At the present the known feedthrough insulator are not able to sense the electric field and/or the magnetic field generated by the live rod of connection and, besides, they are not able to sense the electric field and/or the magnetic field generated by the live rod of connection without being affected by the surrounding electrical fields and/or magnetic fields generated by other live conductors located nearby.

OBJECT OF THE INVENTION

The object of the present invention is to overcome the aforementioned drawbacks.

The invention, which is defined in the claims, resolves the problem of creating a feedthrough insulator characterized by the fact to comprise:

a central rod of connection which extends along a longitudinal axis;

a sleeve positioned coaxial around said rod of connection with the respective circular shell radially spaced with respect to the central rod;

a sensor of electric field and/or of magnetic field positioned in proximity of the inner surface of said shell of the sleeve; and

a carrying body formed by dielectric material able to contain and to embed said central rod said sleeve and said sensor.

BRIEF DESCRIPTION OF THE ATTACHED FIGURES

The following description of the capacitive sensor proposed by the present invention, in various practical embodiments, is provided by way of non-limiting example and makes reference to the appended drawings, in which:

FIG. 1 shows schematically a first embodiment of the feedthrough insulator as a section view with respect to a longitudinal central plan;

FIG. 2 shows schematically a second embodiment of the feedthrough insulator as a section view with respect to a longitudinal central plan;

FIG. 3 shows schematically a third embodiment of the feedthrough insulator as a section view with respect to a longitudinal central plan;

FIG. 4 shows schematically a fourth embodiment of the feedthrough insulator as a section view with respect to a longitudinal central plan.

FIRST EMBODIMENT

With reference to FIG. 1 it illustrates a first embodiment of the feedthrough insulator insulating according to the present invention and, more particularly, a basic embodiment.

The basic feedthrough insulator, here indicated with 00, substantially comprises:>_a central rod 10 of connection which extends along a longitudinal axis 10 y;>_a sleeve 20 positioned coaxial around said rod of connection 10 with the respective shell 21 radially spaced D-21 with respect to the central rod 10;>_a sensor 30 of electric field and/or of magnetic field positioned in proximity of the inner surface 22 of the shell 21 of the sleeve 20, in which said sensor 30 has preferably the form of a diskette;>_a carrying body 40 formed by dielectric material, having a conic-cylindrical conformation, and able to contain and/or to position and/or to englobe said central rod 10, said sleeve 20 and said sensor 30 of electric field and/or magnetic field.

Furthermore, by way of non-limiting example, said feedthrough insulator 00 can further comprise a conductor 50 which is able to connect said sensor 30 of electric field and/or of magnetic field with a device 51 positioned on the external surface 41 the body 40 of dielectric material, in which said device 51 can be a device for connection or a display device, as for example an unit able to elaborate the signals received by the conductor 50 and able to indicate on a display the voltage and/or the current sensed, or a different device.

With reference to FIG. 1, the sleeve 20 has a longitudinal length L-20 and the sensor 30 of electric field and/or of magnetic field is positioned in an intermediary point with respect to said longitudinal length L-20, in which said longitudinal length L_20 has a length able to prevent the harmful-undesired electrical field lines generated by surrounding conductors to sink-close on said sensor 30.

?The sleeve 20 is preferably connected to earth or to a reference potential and, furthermore, the distance D-21 between the sleeve 20 and the rod 10 is preferably a minimum distance such that the dielectric strength of the dielectric body 40 is not exceeded, thus ensuring the requisite degree of insulation.

The sensor 30 of electric field and/or of magnetic field is electrically spaced with respect to the rod 10 with a minimum distance such that the dielectric strength of the dielectric body is not exceeded, thus ensuring the requisite degree of insulation.

DESCRIPTION OF THE SECOND, THIRD AND FOURTH EMBODIMENT

With reference to the FIG. 2, FIG. 3 and FIG. 4, they, respectively, illustrate a second, a third and a fourth embodiment of the feedthrough insulator according to the present invention.

With reference to the second, third and fourth embodiments, indicated with 100, 200, 300, in the respective FIGS. 2, 3 and 4, the feedthrough insulator comprises a rod 10, a sleeve 20, a sensor 30 and a carrying body 40 of dielectric material as in the first embodiment 00 of FIG. 1 and, furthermore, at least a screen element, indicated with 161 or 162 in FIG. 2, with 261 or 262 in FIG. 3, with 361 or 362 in FIG. 4, in which said screen element 161/162 261/262 361/362 is positioned near of at least one of the two openings 23 sx and 23 dx configured on the opposite longitudinal ends of the sleeve 20, in which said screen element, 161 or 162 in FIG. 2, 261 or 262 in FIG. 3, 361 or 362 in FIG. 4, is able to screen the entry of the harmful-undesired electrical field lines generated by other surrounding live conductors, so that said harmful-undesired electrical field lines do not sink-close on said sensor 30. ?Preferably, said screen element/s, 161 and/or 162 in FIG. 2, 261 and/or 262 in FIG. 3, 361 and/or 362 in FIG. 4, is/are put on (around) the rod 10 and, for the reasons that will result subsequently, put on (around) the rod 10 in a longitudinally slidable and longitudinally adjustable manner.

In this context, for example, said rod 10 can be equipped with an external thread while said screen element/s, 161 and/or 162 FIG. 2, 261 and/or 262 in FIG. 3, 361 and/or 362 in FIG. 4, can be equipped with an internal thread, in which said two threads are fit together, with the purpose to allow the longitudinal translation/positioning of the screen elements with respect to the rod 10.

DETAILED DESCRIPTION OF THE SECOND EMBODIMENT

With reference to FIG. 2 the illustrated second embodiment is here indicated with 100.

In said second embodiment at least a screen element is shaped in the form of a disk, 161, 162, and said disk, 161, 162, is positioned to a determined longitudinal distance, D-161, D-162, with respect to the respective longitudinal end, 24 sx, 24 dx, of the sleeve 20, in which said distance, D-161, D-162, is preferably the minimum distance such that the dielectric strength of the dielectric body 40 is not exceeded, thus ensuring the requisite degree of insulation.

DETAILED DESCRIPTION OF THE THIRD EMBODIMENT

With reference to FIG. 3 the illustrated third embodiment is here indicated with 200.

In said third embodiment at least a screen element is shaped in the form of a truncated cone, 261, 262, with smaller basis oriented toward a respective opening, 23 sx, 23 dx, of the sleeve 20.

The screen element, 261, 262, in the for of a truncated cone is positioned to a determined longitudinal distance, D-261, D-262, with respect to the respective longitudinal end, 24 sx, 24 dx, of the sleeve 20, in which said distance, D-261, D262, is preferably the minimum distance such that the dielectric strength of the dielectric body 40 is not exceeded, thus ensuring the requisite degree of insulation.

DETAILED DESCRIPTION OF THE FOURTH EMBODIMENT

With reference to the FIG. 4 the illustrated fourth embodiment is here indicated with 300.

?Said fourth screen element is shaped in the form of a funnel, 361, 362, with the stem oriented towards the opening, 23 sx, 23 dx, of the sleeve 20.

Said screen element in the form of a funnel, 361, 362, has its sides, 363, 364, with a profile rounded in a convex manner with respect to the longitudinal axe 10 y of the rod 10. ?More in particular said funnel, 361, 362, has the sides, 363, 364, rounded in a convex manner with respect to the longitudinal axis by of the rod 10 with a radius of curvature having determined length, indicated with R-363 and R-364, in which the length of the radius of curvature, R-363, R-364, preferably correspond to the minimum distance to be maintained between the circular perimeter, 24 sx, 24 dx, of the sleeve 20 with respect to the funnel, 361, 362, such that the dielectric strength of the dielectric body 40 is not exceeded, thus ensuring the requisite degree of insulation.

Furthermore, said screen element in the form of a funnel, 361, 362, is positioned next to the respective opening, 23 sx, 23 dx, of the sleeve 20 and spaced with respect to said sleeve with a distance equal to the length of the radius R-363, R-364, of the rounded sides of the funnel 361, 362. 

1. A feedthrough insulator comprising: a central rod of connection which extends along a longitudinal axis; a sleeve positioned coaxial around said rod of connection with the respective circular shell radially spaced with respect to the central rod; a sensor of electric field and/or of magnetic field, positioned in proximity of the inner surface of said shell of the sleeve; a carrying body formed by dielectric material able to contain and to embed said central rod, said sleeve and said sensor.
 2. The feedthrough insulator according to claim 1, further comprising: a conductor which is able to connect said sensor with a device positioned on the external surface the body.
 3. The feedthrough insulator according to claim 1, wherein said sleeve has a longitudinal extension and the sensor is positioned in an intermediary point with respect to said longitudinal extension.
 4. The feedthrough insulator according to claim 1, wherein said sleeve has a longitudinal extension in which said longitudinal length has a length able to prevent the harmful-undesired electrical field lines generated by surrounding conductors to sink-close on said sensor.
 5. The feedthrough insulator according to claim 1, wherein said sleeve is connected to the ground or to a reference potential.
 6. The feedthrough insulator insulating according to claim 1, wherein said sensor is electrically isolated with respect to the sleeve.
 7. The feedthrough insulator according to claim 1, further comprising: at least one screen element, positioned near at least one of the two openings configured at the opposite longitudinal ends of the sleeve and able to screen the entry of the of the harmful-undesired electrical field lines generated by surrounding conductors so that said harmful-undesired electrical field lines do not sink-close on said sensor.
 8. The feedthrough insulator according to the claim 7, wherein said at least one screen element is put on the rod.
 9. The feedthrough insulator insulating according to claim 7, wherein said at least one screen element is put on the rod in a longitudinally slidable and longitudinally adjustable manner.
 10. The feedthrough insulator according to claim 7, wherein said rod is equipped with an external thread, said screen element being equipped with an internal thread, said two threads fitting together with the purpose to allow the longitudinal positioning of the screen element with respect to the rod.
 11. The feedthrough insulator insulating according claim 7, wherein said at least one screen element is a disk.
 12. The feedthrough insulator according to claim 11, wherein said disk is positioned to a determined longitudinal spacing with respect to the respective longitudinal end of the sleeve, said spacing being the minimum spacing such that the dielectric strength of the dielectric body is not exceeded thus ensuring the requisite degree of insulation.
 13. The feedthrough insulator according to claim 7, wherein said at least one screen element is a frustocone with smaller basis oriented toward a respective opening of the sleeve.
 14. The feedthrough insulator insulating according to claim 13, wherein the frustocone is positioned to a determined longitudinal spacing with respect to the respective longitudinal end of the sleeve, said spacing being preferably the minimum spacing such that the dielectric strength of the dielectric body is not exceeded thus ensuring the requisite degree of insulation.
 15. The feedthrough insulator insulating according to claim 7, wherein said at least one screen element is a funnel with stem oriented toward an opening of the sleeve.
 16. The feedthrough insulator insulating according to claim 15, wherein sides of the funnel have a profile rounded in a convex manner with respect to the longitudinal axe of the rod.
 17. The feedthrough insulator according to claim 15, wherein the sides of said funnel are rounded in a convex manner with respect to the longitudinal axis of the rod with a radius of curvature having determined length corresponding to the minimum spacing to be maintained between the circular perimeter of the sleeve with respect to the funnel such that the dielectric strength of the dielectric body is not exceeded thus ensuring the requisite degree of insulation.
 18. The feedthrough insulator according to claim 15, wherein the funnel is positioned next to the respective opening of the sleeve and spaced with respect to said sleeve with a spacing equal to the length of the radius of the rounded sides of the funnel. 